Moffat, the show's executive producer, writer and co-creator, said: "It's been a long time since Sherlock Holmes jumped off that roof - it's time to reveal the truth about what happened between him and the pavement."

Executive producer, writer and co-creator Gatiss added: "Sherlock and John Watson are back at last! And they're just where we want them - on the streets of London having mad, thrilling adventures."